So-called double-lock connectors in which, for the purpose of securing or reinforcing contacts in insulating housing, two means of securing are provided are widely used in automotive and some other applications. These two means are: housing lances extending from the housing internal wall in the contact cavity (primary means of securing) and a locking device made separately from the housing (secondary means of securing). An example of such a connector is shown in FIG. 5, and its design was proposed by the present applicant JP (1992)-137474. This connector 100 has a locking device 110 which reliably joins the connector and the end insertion piece 112. Because of this, the retention strength of the contacts (not shown in the drawing) is adequately increased, and incompletely inserted contacts can be easily detected.
In the insulating housing 112 of said conventional connector 100, a flange 108 protruding from a side surface 106 of the insulating housing is formed in the vicinity of an insertion opening 104 for the locking device 110. This flange 108 plays the role of the rest for fingers when the connector 110 is pulled out of the matching connector (not shown in the drawing) and, at the same time, it prevents the locking device 110 from useless moving form temporary latched position to the completely latched position.
However, a disadvantage of this design is that in the completely latched position of the locking device 110 becomes flush with the side surface 106, and the flange 108 prevents visual observation of correctness of the position of the locking device 110. It is especially important for harness assembly workers who have to deal with moving the locking device 110 from temporary latched position to fully latched position in the insulating housing 102 after inserting contacts with electric wires connected to them (not shown in the drawing), since they have to look at the connector 100 from the contact insertion side of the insulating housing 102.
In addition, since multiple lugs 114 for complete latching are arranged along the long side of the locking device 110 which is long and narrow, there is a danger that not all lugs 114 lock simultaneously, thus leaving the locking device 110 inclined relative to the side surface 106 of the insulating housing 102. Therefore, there is a danger that the locking device 110 in automotive harness will be incompletely attached since it is difficult to check the position of the locking device 110 by looking from the contact insertion side of the insulating housing 102.
Therefore, the purpose of this invention was to offer a connector free of the above mentioned disadvantages, that is to prevent inclined position of the locking device inserted from a side of the insulating housing and to provide visual means for checking completeness of the latching by the locking device.